const data = [
  { month: 'Jan', city: 'Tokyo', temperature: 7 },
  { month: 'Jan', city: 'London', temperature: 3.9 },
  { month: 'Feb', city: 'Tokyo', temperature: 6.9 },
  { month: 'Feb', city: 'London', temperature: 4.2 },
  { month: 'Mar', city: 'Tokyo', temperature: 9.5 },
  { month: 'Mar', city: 'London', temperature: 5.7 },
  { month: 'Apr', city: 'Tokyo', temperature: 14.5 },
  { month: 'Apr', city: 'London', temperature: 8.5 },
  { month: 'May', city: 'Tokyo', temperature: 18.4 },
  { month: 'May', city: 'London', temperature: 11.9 },
  { month: 'Jun', city: 'Tokyo', temperature: 21.5 },
  { month: 'Jun', city: 'London', temperature: 15.2 },
  { month: 'Jul', city: 'Tokyo', temperature: 25.2 },
  { month: 'Jul', city: 'London', temperature: 17 },
  { month: 'Aug', city: 'Tokyo', temperature: 26.5 },
  { month: 'Aug', city: 'London', temperature: 16.6 },
  { month: 'Sep', city: 'Tokyo', temperature: 23.3 },
  { month: 'Sep', city: 'London', temperature: 14.2 },
  { month: 'Oct', city: 'Tokyo', temperature: 18.3 },
  { month: 'Oct', city: 'London', temperature: 10.3 },
  { month: 'Nov', city: 'Tokyo', temperature: 13.9 },
  { month: 'Nov', city: 'London', temperature: 6.6 },
  { month: 'Dec', city: 'Tokyo', temperature: 9.6 },
  { month: 'Dec', city: 'London', temperature: 4.8 }
];

const chart = new G2.Chart({
  container: 'container',
  forceFit: true,
  height: 500
});
chart.source(data, {
  month: {
    range: [ 0, 1 ]
  }
});
chart.tooltip({
  crosshairs: {
    type: 'line'
  }
});
chart.axis('temperature', {
  label: {
    formatter: val => {
      return val + '°C';
    }
  }
});
chart.line().position('month*temperature').color('city');
chart.point().position('month*temperature').color('city')
  .size(4)
  .shape('circle')
  .style({
    stroke: '#fff',
    lineWidth: 1
  });
chart.render();
